what3words API - online and offline

We encourage developers to integrate what3words into their applications, and we want to make this as easy as possible.

We offer two ways to access our API: online, documented in detail on this portal, and offline.

Our focus is on widespread adoption: as such, access to our online API is currently completely free and you can sign up for an API key below. We intend to introduce different pricing levels in the future (depending on volume and type of requests), but there will always be ways to use it for free, particularly for low volume.

For access to our offline SDK we require a separate licence agreement to be signed and, depending on your application, we may waive the license fee. Please contact us on api-sales@what3words.com for more information.

Please explore our API portal: you should find all the details you need to use our API, as well as additional useful information to help you make the most of what3words.

Online API Sign up   Offline SDK Enquiry

Tech Spec

The JSON API has 14 methods - see the reference and sample code for more info.

Reference & sample code

Brand Assets and Style Guide

You are allowed (and encouraged!) to use what3words brand assets within your app/software where appropriate.

We also ask that you follow our very simple style guide when referring to what3words.

Please get in touch if you want anything else.

Batch Conversion Tools

Convert a batch of lat,long co-ordinates to 3 words, or vice versa using our free batch conversion tools.

Batch conversion tool

App URL Scheme

The what3words iOS and Android apps include a URL scheme to allow you to link directly into the apps.

Tech Blog

Read about existing w3w API implementations, news and ideas in our Tech blog


For API technical support enquiries please email api-support@what3words.com

For API account enquiries please email api-sales@what3words.com